Robust Wideband Beamspace Adaptive Beamforming for Mainlobe Jamming in Underwater Environment

In underwater acoustic detection, wideband array technology is recognized for its robust anti-interference capabilities and enhanced target information acquisition. Traditional wideband adaptive beamforming techniques grapple with the challenge of mainlobe distortion in the presence of mianlobe jamming, which diminishes the effectiveness of target detection. Addressing this predicament, we propose an innovative wideband beamspace adaptive beamforming approach. This approach capitalizes on the unique structure of beamspace to devise auxiliary beams expressly engineered to present a minimal amplitude-frequency response within the main beam's mainlobe region. We further employ the spatial response variation strategy to construct a frequency-invariant beamformer, capable of producing consistently oriented beams across a spectrum of frequencies. Subsequently, we decompose the auxiliary beam's covariance matrix and reconstitute the covariance matrix within the beamspace. Such a method preserves the integrity of the mainlobe. The simulation outcomes corroborate the efficacy of our proposed method, confirming its ability to not only safeguard the mainlobe against distortion but also attenuate sidelobe interference and assure commendable frequency uniformity, all achieved without reliance on prior knowledge regarding the nature of the interference.